A magnetic type encoder device includes, for example, as shown in FIG. 21, a magnetic sensor device 1001 provided with a magneto-resistive element on its sensor face and a magnetic scale 1009 which is provided with a permanent magnet and is relatively moved with respect to the magnetic sensor device 1001. The magnetic scale 1009 is formed with a track where an “N”-pole and an “S”-pole are alternately arranged along a relatively moving direction with respect to the magnetic sensor device 1001. Further, in the magnetic sensor device 1001, a rigid board 1010a of two pieces of rigid boards is formed with a “+a” phase magnetic resistance pattern 1025(+a) which is a magnetic resistance pattern of phase “A” and a “+b” phase magnetic resistance pattern 1025(+b) which is a magnetic resistance pattern of phase “B”. The other rigid board 1010b is formed with a “−a” phase magnetic resistance pattern 1025(−a) which is a magnetic resistance pattern of phase “A” and a “−b” phase magnetic resistance pattern 1025(−b) which is a magnetic resistance pattern of phase “B”. These two pieces of the rigid boards 1010a and 1010b are disposed to be faced each other. The magnetic resistance pattern of phase “A” and the magnetic resistance pattern of phase “B” detect movement of the magnetic scale 1009 with a phase difference of 90°. On the other hand, the “+a” phase magnetic resistance pattern 1025(+a) and the “−a” phase magnetic resistance pattern 1025(−a) detect movement of the magnetic scale 1009 with a phase difference of 180° and thus moving detection of the magnetic scale 1009 can be performed from a differential output of them. Further, the “+b” phase magnetic resistance pattern 1025(+b) and the “−b” phase magnetic resistance pattern 1025(−b) detect movement of the magnetic scale 1009 with a phase difference of 180° and thus moving detection of the magnetic scale 1009 can be performed from a differential output of them (see, for example, Patent Reference 1 or 2).
[Patent Reference 1] Japanese Patent Laid-Open No. 2005-249774
[Patent Reference 2] Japanese Patent Laid-Open No. Hei 6-207834